Fermentative Production of Naringinase from Aspergillus niger van Tieghem MTCC 2425 Using Citrus Wastes: Process...

Area of Science:

• Biotechnology
• Enzymology
• Industrial Microbiology

Background:

• Naringinase is essential for debittering citrus juices through enzymatic hydrolysis of naringin.
• Optimizing naringinase production is key for efficient industrial application.

Purpose of the Study:

• To optimize submerged fermentation conditions for enhanced naringinase production by Aspergillus niger MTCC 2425.
• To characterize the partially purified naringinase and assess its stability.

Main Methods:

• Plackett-Burman and Central Composite Designs were used to optimize fermentation parameters (pH, temperature, inducer concentration).
• Naringin from citrus waste served as the inducer.
• Ion exchange chromatography and SDS-PAGE were employed for partial purification and molecular weight determination.

Main Results:

• Optimal fermentation conditions were determined as pH 4.7, 29.8°C, and 14.9 g·L⁻¹ inducer concentration, yielding 545.2 IU·g⁻¹ naringinase activity.
• Partial purification via ion exchange chromatography resulted in a 9.92-fold increase in specific activity (5460 IU·g⁻¹).
• The enzyme exhibited optimal stability at pH 5 and 50°C, retaining full activity for 150 days at 4°C.

Conclusions:

• The optimized submerged fermentation process significantly enhances naringinase production.
• The characterized naringinase demonstrates promising stability for industrial applications in citrus juice debittering.